 <!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="Vue/vue.js"></script>
    <script src="Vue/vue-router.js"></script>
    <style>

        #app{
            height: 100%;
            display:flex;
            flex-direction:column;
        }
       .top{
           width: 400px;
           height: 200px;
           background-color: aquamarine;
       }
        .content{
            flex: 1;
            background-color: red;
        }
        .d1{

            width: 200px;
            height:200px;
            border: 1px solid black;
            background-color: palevioletred;
        }
        .bottom{
            width: 400px;
            height: 200px;
            background-color: blue;
        }
    </style>
</head>
<body>
<div id="app">
<div class="top"></div>
<div class="content">
    <div class="d1">d1</div>

</div>
<div class="bottom"></div>
</div>
<script>

</script>
</body>
</html>